Johnson Pump 09-810B-1 F4 Impeller (MC97)

The Johnson Pump 09-810B-1 F4 Impeller (MC97) is an essential replacement component for marine cooling systems found on a wide range of inboard and outboard engines. After years of running boats in saltwater and freshwater environments, any experienced boater knows that impeller wear is one of the most common maintenance issues you'll face. This OEM-spec impeller restores reliable water circulation, preventing catastrophic overheating that can strand you miles from the dock or damage an engine beyond economical repair.

The F4 impeller design delivers consistent flow rates and pressure stability across varying RPM ranges, which is critical when you're running hard in shallow water or during extended high-throttle operations. Johnson Pump's engineering ensures tight tolerances and durable elastomer composition, allowing the impeller to withstand thermal cycling and the corrosive effects of salt spray without premature degradation. The MC97 mounting configuration integrates directly into OEM pump housings without modification, meaning installation is straightforward and you avoid custom fabrication delays or compatibility headaches.

This impeller suits both weekend cruisers and serious anglers who depend on their engines to perform day in and day out. Whether you're running a saltwater charter, maintaining a fishing vessel, or keeping a family ski boat in peak condition, the Johnson Pump 09-810B-1 F4 Impeller (MC97) belongs in your spares kit. Routine impeller replacement is recommended every 300 to 500 operating hours to ensure optimal performance.